package hu;

import java.util.*;

/**
 * 暂且不做，以后再做
 */
public class hu50 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String str = sc.nextLine();
        str = str.replace("[","(");
        str = str.replace("]",")");
        str = str.replace("{","(");
        str = str.replace("}",")");
        Stack<Character> nums = new Stack<>();
        Stack<Character> fu = new Stack<>();
        for (int i = 0; i < str.length(); i++) {
            if(str.charAt(i) <= '9' && str.charAt(i) >= '0')
                nums.push(str.charAt(i));

        }
    }
}
